Semiconductor laser inspection apparatus

ABSTRACT

A semiconductor laser device (2) is placed on a first heating-cooling device (1). A probe holder (4) is attached on a second heating-cooling device (3). A measurement probe (8) is fixed to a distal end of the probe holder (4). A fine movement table (9) moves the second heating-cooling device (3) and the probe holder (4) so that a distal end of the measurement probe (8) contacts the semiconductor laser device (2). An inspection apparatus (10) inputs an inspection signal to the semiconductor laser device (2) through the measurement probe (8).

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Divisional of U.S. Pat. Application No. 18/004,228filed Jan. 4, 2023, which was the U.S. National Stage of InternationalApplication No. PCT/JP2020/045110 filed Dec. 3, 2020, the entire contentof which is incorporated herein by reference.

FIELD

The present disclosure relates to a semiconductor laser inspectionapparatus and a semiconductor laser inspection method that inspect thecharacteristics of a semiconductor laser device with a probe broughtinto contact with the semiconductor laser device.

BACKGROUND

A diced semiconductor laser device is placed on a jig including aheating-cooling device and is subjected to characteristic inspection incontact with a probe. When the probe at room temperature contacts theheated or cooled semiconductor laser, the characteristics of thesemiconductor laser device vary due to the temperature differencetherebetween and measurement variance occurs. For this, a technology ofheating the probe to the temperature of a semiconductor wafer by aheating apparatus at inspection of the wafer has been disclosed.Accordingly, it is possible to prevent heat removal from thesemiconductor wafer and reduce measurement variance. Moreover, it ispossible to reduce deformation of the probe at contact and stabilize thecontact.

However, conventionally, the heating apparatus has been providedseparately from the probe, and thus the probe has needed to be heated bythe heating apparatus again after inspection. For this, an inspectionapparatus in which the heating apparatus is attached to the probe hasbeen disclosed (refer to PTL 1, for example).

Citation List Patent Literature

[PTL 1] JP H10-90345 A

SUMMARY Technical Problem

To cool a probe, a Peltier element needs to be installed on the probe.The size of a typical Peltier element is equal to or larger than 10 mm ×10 mm. The size of a probe used for semiconductor inspection typicallyincludes the diameter of 1 mm and the length of 20 to 30 mmapproximately. Thus, no space in which the typical Peltier element isprovided is available near the probe. In a case of a Peltier elementhaving a smaller size, it is difficult to externally extend a coveredwire through which current flows to the Peltier element. When a Peltierelement is installed on a probe, a support component that supports themgenerates heat, and thus a cooling mechanism of water cooling or thelike is needed. However, only a hole having a diameter of severalmillimeters approximately is opened at the support component, whichallows flow of only a small amount of cooling water, and thus sufficientcooling is impossible. As a result, the probe cannot be cooled and thecharacteristics of a semiconductor laser device cannot be prevented fromvarying at contact with the probe.

The present disclosure is intended to solve the above-described problemand obtain a semiconductor laser inspection apparatus and asemiconductor laser inspection method that are capable of preventing thecharacteristics of a semiconductor laser device from varying at contactwith a probe.

Solution to Problem

A semiconductor laser inspection apparatus according to the presentdisclosure includes: a first heating-cooling device on which asemiconductor laser device is placed; a second heating-cooling device; aprobe holder attached on the second heating-cooling device; ameasurement probe fixed to a distal end of the probe holder; a finemovement table moving the second heating-cooling device and the probeholder so that a distal end of the measurement probe contacts thesemiconductor laser device; and an inspection apparatus inputting aninspection signal to the semiconductor laser device through themeasurement probe.

Advantageous Effects of Invention

In the present disclosure, the semiconductor laser device is placed onthe first heating-cooling device, and the probe holder is attached onthe second heating-cooling device. Since the first and secondheating-cooling devices are capable of controlling temperature not onlyto the high temperature side but also to the low temperature side, thetemperature of the semiconductor laser device and the temperature of themeasurement probe can be made close to each other. Accordingly, thecharacteristics of the semiconductor laser device can be prevented fromvarying at contact with the measurement probe.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating a semiconductor laser inspectionapparatus according to Embodiment 1.

FIG. 2 is a block diagram illustrating a semiconductor laser inspectionapparatus according to Embodiment 2.

FIG. 3 is an enlarged side view of a region A surrounded by a dashedline in FIG. 2 .

FIG. 4 is a block diagram illustrating a modification of thesemiconductor laser inspection apparatus according to Embodiment 2.

FIG. 5 is a block diagram illustrating a semiconductor laser inspectionapparatus according to of Embodiment 3.

FIG. 6 is an enlarged side view of a region A surrounded by a dashedline in FIG. 5 .

FIG. 7 is a block diagram illustrating a semiconductor laser inspectionapparatus according to of Embodiment 4.

FIG. 8 is a block diagram illustrating a semiconductor laser inspectionapparatus according to of Embodiment 5.

FIG. 9 is a diagram related to measurement of time variation of thewavelength of light emitted from the semiconductor laser device at theset temperature of the measurement probe.

FIG. 10 is a block diagram for description of a semiconductor laserinspection method according to Embodiment 6.

FIG. 11 is a block diagram for description of a semiconductor laserinspection method according to Embodiment 7.

DESCRIPTION OF EMBODIMENTS

A semiconductor laser inspection apparatus and a semiconductor laserinspection method according to the embodiments of the present disclosurewill be described with reference to the drawings. The same componentswill be denoted by the same symbols, and the repeated descriptionthereof may be omitted.

Embodiment 1

FIG. 1 is a block diagram illustrating a semiconductor laser inspectionapparatus according to Embodiment 1. A heating-cooling device 1 is astage on which a semiconductor laser device 2 is placed. A probe holder4 is attached on a heating-cooling device 3. The heating-cooling device1 and the heating-cooling device 3 each include, for example, a Peltierelement capable of controlling temperature not only to the hightemperature side but also to the low temperature side.

A temperature sensor 5 is built in the heating-cooling device 1 andmeasures the temperature of the heating-cooling device 1. A temperaturesensor 6 is built in the heating-cooling device 3 and measures thetemperature of the heating-cooling device 3. In the present embodiment,a control unit 7 sets the temperature of the heating-cooling device 1and the temperature of the heating-cooling device 3 to the same valuebased on measurement results of the temperature sensors 5 and 6.

A measurement probe 8 is fixed to the distal end of the probe holder 4.A fine movement table 9 moves the heating-cooling device 3 and the probeholder 4 in the up-down direction and the horizontal direction so thatthe distal end of the measurement probe 8 contacts the semiconductorlaser device 2 placed on the heating-cooling device 1.

An inspection apparatus 10 includes a signal generator 11, an LD drivepower source 12, and a bias tee 13. A modulated signal output from thesignal generator 11 and constant voltage output from the LD drive powersource 12 become an inspection signal through coupling at the bias tee13. The inspection apparatus 10 inputs the inspection signal to thesemiconductor laser device 2 through the measurement probe 8. Thesemiconductor laser device 2 is driven by the inspection signal toperform characteristic inspection of the semiconductor laser device 2.

Note that, when measurement is performed at room temperature lower than25° C., dew condensation occurs to the measurement probe 8 or thesemiconductor laser device 2 and characteristic value variation or shortcircuit during the measurement potentially occurs. Thus, the entireapparatus needs to be enclosed in a box made of acrylic or the like andfilled with dry air or N₂ to prevent dew condensation.

In the present embodiment, the semiconductor laser device 2 is placed onthe heating-cooling device 1, and the probe holder 4 is attached on theheating-cooling device 3. Since the heating-cooling device 1 and theheating-cooling device 3 are capable of controlling temperature not onlyto the high temperature side but also to the low temperature side, thetemperature of the semiconductor laser device 2 and the temperature ofthe measurement probe 8 can be made close to each other. Accordingly,the characteristics of the semiconductor laser device 2 can be preventedfrom varying at contact with the measurement probe 8.

The control unit 7 sets the temperature of the heating-cooling device 1and the temperature of the heating-cooling device 3 to the same value.In this state, the measurement probe 8 is brought into contact with thesemiconductor laser device 2 when measurement is performed, andaccordingly, heat can be prevented from flowing into or out of thesemiconductor laser device 2 at contact with the measurement probe 8. Asa result, measurement variance can be prevented from occurring due tovariation of the characteristics of the semiconductor laser device 2.

In a conventional inspection apparatus, it is needed to move ameasurement probe to a heating-cooling device and heat and cool thedistal end of a probe each time measurement is performed. However, inthe present embodiment, since the heating-cooling device 3 can heat andcool the measurement probe 8 through the probe holder 4, the measurementprobe 8 does not need to be moved for heating and cooling.

With a conventional inspection apparatus in which a measurement probe isintegrated with a heating device, it is impossible to controltemperature to the low temperature side. Furthermore, it is impossibleto allocate, near a probe, a space for providing a Peltier element and acooling mechanism of water cooling or the like. However, in the presentembodiment, the probe holder 4 is attached on the heating-cooling device3. Accordingly, the heating-cooling device 3 can cool the measurementprobe 8 through the probe holder 4.

The measurement probe 8 needs to have impedance matching for ahigh-frequency wave of several tens GHz. Accordingly, no freedom isavailable for designing of a probe needle of the measurement probe 8 andit is extremely difficult to extend the measurement probe 8 from theheating-cooling device 3 to the semiconductor laser device 2, and thusthe probe holder 4 needs to be interposed therebetween. For this reason,the temperature difference from the semiconductor laser device 2 can bereduced when the difference between the temperature of theheating-cooling device 3 and the temperature of the distal end of themeasurement probe 8 is as small as possible. Thus, the material of theprobe holder 4 is preferably copper, aluminum, or the like having athermal conductivity higher than 200 [W/m·K].

Embodiment 2

FIG. 2 is a block diagram illustrating a semiconductor laser inspectionapparatus according to Embodiment 2. When measurement is performed, thesemiconductor laser device 2 is placed on a thin metal plate 15, whichis provided on a heat insulation material 14, in place of theheating-cooling device 1 of Embodiment 1. One end of a spring 16 isconnected to the upper surface of the metal plate 15, and the other endof the spring 16 is connected to the lower surface of the probe holder4. The spring 16 thermally couples the metal plate 15 and the probeholder 4. The other configuration is the same as in Embodiment 1.

FIG. 3 is an enlarged side view of a region A surrounded by a dashedline in FIG. 2 . A spring bracket 17 is fixed to the upper surface ofthe metal plate 15 by a screw or the like. A spring fixation member 18contacts the lower surface of the probe holder 4. A spring fixation pin19 is attached to the spring fixation member 18. The spring 16 isattached to the spring fixation pin 19. The outer shape of the springfixation pin 19 and the inner diameter of the spring 16 are preferablyas close to each other as possible so that the spring 16 is stronglyfixed to the spring fixation pin 19 and heat is more likely to betransferred. The distal end of the spring 16 is inserted into the springbracket 17 with the spring 16 being attached to the spring fixationmember 18. In this state, the probe holder 4 is placed on the springfixation member 18.

Heat from the probe holder 4 needs to be transferred to the metal plate15. Thus, the spring 16, the spring bracket 17, the spring fixation pin19, and the spring fixation member 18 are each preferably made of ametal having a thermal conductivity higher than 200 [W/m-K] and arepreferably made of the same material to obtain the same linear expansioncoefficient.

The spring fixation member 18 and the probe holder 4 are not fixed toeach other, and thus the measurement probe 8 can be moved not only inthe height direction but also in the horizontal direction with thespring fixation member 18 contacting the probe holder 4. To obtainmovability, a contact part between the lower surface of the probe holder4 and the spring fixation member 18 may be mirrored and lubricant may beapplied to the contact part. To obtain thermal conductivity, heatconduction grease may be applied to the contact part. To prevent thespring 16 from protruding to a side, the depth of the spring bracket 17is preferably deep enough that part of the spring fixation pin 19 isalways in the spring bracket 17.

In the present embodiment, the probe holder 4 is attached on theheating-cooling device 3, and the spring 16 thermally couples the metalplate 15 and the probe holder 4. Thus, the temperature of thesemiconductor laser device 2 and the temperature of the measurementprobe 8 can be made close to each other by transferring heat from theone heating-cooling device 3 to the measurement probe 8 and the metalplate 15. Accordingly, the characteristics of the semiconductor laserdevice 2 can be prevented from varying at contact with the measurementprobe 8.

FIG. 4 is a block diagram illustrating a modification of thesemiconductor laser inspection apparatus according to Embodiment 2.Supports 20 are attached to four corners of the lower surface of themetal plate 15 in place of the heat insulation material 14 of Embodiment2. A hollow space is provided below the metal plate 15. The material ofthe supports 20 is preferably resin, ceramic, or the like, which is lessunlikely to transfer heat. The above-described effects can be obtainedin this case as well.

Embodiment 3

FIG. 5 is a block diagram illustrating a semiconductor laser inspectionapparatus according to of Embodiment 3. The probe holder 4 is attachedon a heat insulation material 21 in place of the heating-cooling device3 of Embodiment 1. The fine movement table 9 moves the heat insulationmaterial 21 and the probe holder 4 in the up-down direction and thehorizontal direction. One end of the spring 16 is connected to the uppersurface of the heating-cooling device 1, and the other end of the spring16 is connected to the lower surface of the probe holder 4. The spring16 thermally couples the heating-cooling device 1 and the probe holder4. The other configuration is the same as in Embodiment 1.

FIG. 6 is an enlarged side view of a region A surrounded by a dashedline in FIG. 5 . The spring fixation member 18 is fixed to the uppersurface of the heating-cooling device 1 by a screw or the like. Thespring fixation pin 19 is attached to the spring fixation member 18. Thespring 16 is attached to the spring fixation pin 19. The outer shape ofthe spring fixation pin 19 and the inner diameter of the spring 16 arepreferably as close to each other as possible so that the spring 16 isstrongly fixed to the spring fixation pin 19 and heat is more likely tobe transferred. The spring bracket 17 contacts the lower surface of theprobe holder 4. The distal end of the spring 16 is inserted into thespring bracket 17 with the spring 16 being attached to the springfixation member 18. In this state, the probe holder 4 is placed on thespring bracket 17.

Heat from the heating-cooling device 1 needs to be transferred to themeasurement probe 8. Thus, the spring 16, the spring bracket 17, thespring fixation pin 19, and the spring fixation member 18 are eachpreferably made of a metal having a thermal conductivity higher than 200[W/m-K] and are preferably made of the same material to obtain the samelinear expansion coefficient. The probe holder 4 is made of a metalhaving a thermal conductivity higher than 200 [W/m-K] and preferably hasa smaller size than in Embodiment 2 to reduce heat capacity so that heatis more likely to be transferred to the measurement probe 8.

The spring bracket 17 and the probe holder 4 are not fixed to eachother, and thus the measurement probe 8 can be moved not only in theheight direction but also in the horizontal direction with the springbracket 17 contacting the probe holder 4. To obtain movability, acontact part between the lower surface of the probe holder 4 and thespring bracket 17 may be mirrored and lubricant may be applied to thecontact part. To obtain thermal conductivity, heat conduction grease maybe applied to the contact part. To prevent the spring 16 from protrudingto a side, the depth of the spring bracket 17 is preferably deep enoughthat part of the spring fixation pin 19 is always in the spring bracket17.

In the present embodiment, the spring 16 thermally couples theheating-cooling device 1 on which the semiconductor laser device 2 isplaced and the probe holder 4. Thus, the temperature of thesemiconductor laser device 2 and the temperature of the measurementprobe 8 can be made close to each other by transferring heat from theheating-cooling device 1 to the measurement probe 8 through the spring16 and the probe holder 4. Accordingly, the characteristics of thesemiconductor laser device 2 can be prevented from varying at contactwith the measurement probe 8.

Embodiment 4

FIG. 7 is a block diagram illustrating a semiconductor laser inspectionapparatus according to of Embodiment 4. A temperature sensor 22 isattached in a hole provided at the probe holder 4 or the measurementprobe 8. The temperature sensor 22 measures the temperature of themeasurement probe 8.

The temperature of the heating-cooling device 3 is adjusted in advanceas described below before inspection of the semiconductor laser device 2is started. The control unit 7 sets the heating-cooling device 1 and theheating-cooling device 3 to a temperature T °C at which productinspection is performed, and stabilizes the devices at the temperature.In this state, the temperature sensor 6 measures the temperature of theheating-cooling device 3 and the temperature sensor 22 measures thetemperature of the probe holder 4. A value obtained by subtracting thetemperature measured by the temperature sensor 22 from the temperaturemeasured by the temperature sensor 6 is represented by α. The controlunit 7 resets the temperature of the heating-cooling device 1 to T andresets the temperature of the heating-cooling device 3 to T + α.

Accordingly, the temperature of the measurement probe 8 becomes T °C andthus can be matched with the set temperature of the heating-coolingdevice 1 that sets the temperature of the semiconductor laser device 2.Thus, the temperature of the semiconductor laser device 2 and thetemperature of the measurement probe 8 can be made closer to each otherthan in Embodiment 1. The other configuration and effects are the sameas in Embodiment 1. Note that, since temperature measured by thetemperature sensor 22 at measurement is not used, the temperature sensor22 may be removed after adjustment of the set temperature of theheating-cooling device 3 is completed.

Embodiment 5

FIG. 8 is a block diagram illustrating a semiconductor laser inspectionapparatus according to of Embodiment 5. A wavelength meter 23 configuredto measure the wavelength of light emitted by the semiconductor laserdevice 2 is added to the configuration of Embodiment 1. The temperatureof the heating-cooling device 3 is adjusted in advance as describedbelow before inspection of the semiconductor laser device 2 is started.

The temperature of the heating-cooling device 3 is changed from T - 10°C. to T + 10° C. at the step of 1° C. for the set temperature T of theheating-cooling device 1. Time variation of the wavelength of lightemitted from the semiconductor laser device 2 at contact with themeasurement probe 8 is measured at each temperature. FIG. 9 is a diagramrelated to measurement of time variation of the wavelength of lightemitted from the semiconductor laser device at the set temperature ofthe measurement probe. The horizontal axis represents the settemperature of the measurement probe 8. The vertical axis represents theabsolute value of time variation of the wavelength of light emitted fromthe semiconductor laser device 2 at contact with the measurement probe8. The wavelength time variation is parabolic and has a local minimumpoint.

Subsequently, the wavelength time variation is acquired by changing thetemperature of the heating-cooling device 3 from T′ - 1° C. to T′ + 1°C. at the step of 0.1° C., where T′ represents temperature at which thewavelength time variation has a local minimum. With this measurement, atemperature T″ at which the wavelength time variation has a localminimum is obtained. The control unit 7 sets the heating-cooling device3 to the obtained temperature T″.

The local minimum of the wavelength time variation with theheating-cooling device 3 set to the temperature T″ means that thetemperature of the semiconductor laser device 2 and the temperature ofthe measurement probe 8 are matched. The temperature of thesemiconductor laser device 2 and the temperature of the measurementprobe 8 can be made close to each other by performing theabove-described adjustment. Accordingly, the characteristics of thesemiconductor laser device 2 can be prevented from varying at contactwith the measurement probe 8.

Embodiment 6

FIG. 10 is a block diagram for description of a semiconductor laserinspection method according to Embodiment 6. The wavelength meter 23configured to measure the wavelength of light emitted from a laserdevice placed on the metal plate 15 is added to the configuration ofEmbodiment 2. The temperature of the heating-cooling device 3 isadjusted in advance as described below before inspection of thesemiconductor laser device 2 is started.

A temperature setting laser device 24 for which the relation betweenwavelength and temperature is known in advance is placed on the metalplate 15, the wavelength of light output from the temperature settinglaser device 24 is measured by the wavelength meter 23 while thetemperature of the heating-cooling device 3 is changed, and thetemperature of the heating-cooling device 3 is fixed when the measuredwavelength becomes a wavelength corresponding to a desired temperature.

After the temperature setting laser device 24 is removed from the metalplate 15, the semiconductor laser device 2 is placed on the metal plate15 while the temperature of the heating-cooling device 3 is fixed. Then,similarly to Embodiment 2, inspection of the semiconductor laser device2 is performed with the distal end of the measurement probe 8 broughtinto contact with the semiconductor laser device 2. Accordingly, it ispossible to accurately match a temperature condition under which thesemiconductor laser device 2 is inspected. The other configuration andeffects are the same as in Embodiment 2.

Embodiment 7

FIG. 11 is a block diagram for description of a semiconductor laserinspection method according to Embodiment 7. The wavelength meter 23configured to measure the wavelength of light emitted from a laserdevice placed on the heating-cooling device 1 is added to theconfiguration of Embodiment 3. The temperature of the heating-coolingdevice 1 is adjusted in advance as described below before inspection ofthe semiconductor laser device 2 is started.

The temperature setting laser device 24 for which the relation betweenwavelength and temperature is known in advance is placed on theheating-cooling device 1, the wavelength of light output from thetemperature setting laser device 24 is measured by the wavelength meter23 while the temperature of the heating-cooling device 1 is changed, andthe temperature of the heating-cooling device 1 is fixed when themeasured wavelength becomes a wavelength corresponding to a desiredtemperature.

After the temperature setting laser device 24 is removed from theheating-cooling device 1, the semiconductor laser device 2 is placed onthe heating-cooling device 1 while the temperature of theheating-cooling device 1 is fixed. Then, similarly to Embodiment 3,inspection of the semiconductor laser device 2 is performed with thedistal end of the measurement probe 8 brought into contact with thesemiconductor laser device 2. Accordingly, it is possible to accuratelymatch a temperature condition under which the semiconductor laser device2 is inspected. The other configuration and effects are the same as inEmbodiment 3.

REFERENCE SIGNS LIST

1 first heating-cooling device; 2 semiconductor laser device; 3 secondheating-cooling device; 4 probe holder; 5,6,22 temperature sensor; 7control unit; 8 measurement probe; 9 fine movement table; 10 inspectionapparatus; 15 metal plate; 16 spring; 20 support; 23 wavelength meter;24 temperature setting laser device

1. A semiconductor laser inspection apparatus comprising: a metal plateon which a semiconductor laser device is placed; a heating-coolingdevice; a probe holder attached on the heating-cooling device; ameasurement probe fixed to a distal end of the probe holder; a finemovement table moving the heating-cooling device and the probe holder sothat a distal end of the measurement probe contacts the semiconductorlaser device; an inspection apparatus inputting an inspection signal tothe semiconductor laser device through the measurement probe; and aspring having one end connected to an upper surface of the metal plateand the other end connected to a lower surface of the probe holder,wherein the spring thermally couples the metal plate and the probeholder without the measurement probe interposed therebetween.
 2. Thesemiconductor laser inspection apparatus according to claim 1, whereinsupports are attached to four corners of a lower surface of the metalplate, and a hollow space is provided below the metal plate.
 3. Asemiconductor laser inspection apparatus comprising: a heating-coolingdevice on which a semiconductor laser device is placed; a probe holder;a measurement probe fixed to a distal end of the probe holder; a finemovement table moving the probe holder so that a distal end of themeasurement probe contacts the semiconductor laser device; an inspectionapparatus inputting an inspection signal to the semiconductor laserdevice through the measurement probe; and a spring having one endconnected to an upper surface of the heating-cooling device and theother end connected to a lower surface of the probe holder, wherein thespring thermally couples the heating-cooling device and the probe holderwithout the measurement probe interposed therebetween.
 4. Thesemiconductor laser inspection apparatus according to claim 1, whereinthe spring has a thermal conductivity higher than 200 [W/m•K].
 5. Asemiconductor laser inspection method comprising: placing a temperaturesetting laser device for which a relation between wavelength andtemperature is known in advance on the metal plate of the semiconductorlaser inspection apparatus according to claim 1, measuring a wavelengthof light output from the temperature setting laser device whiletemperature of the heating-cooling device is changed, and fixingtemperature of the heating-cooling device when the measured wavelengthbecomes a wavelength corresponding to a desired temperature; and afterthe temperature setting laser device is removed from the metal plate,placing the semiconductor laser device on the metal plate whiletemperature of the heating-cooling device is fixed, and performinginspection of the semiconductor laser device with the distal end of themeasurement probe brought into contact with the semiconductor laserdevice.
 6. A semiconductor laser inspection method comprising: placing atemperature setting laser device for which a relation between wavelengthand temperature is known in advance on the heating-cooling device of thesemiconductor laser inspection apparatus according to claim 3, measuringa wavelength of light output from the temperature setting laser devicewhile temperature of the heating-cooling device is changed, and fixingtemperature of the heating-cooling device when the measured wavelengthbecomes a wavelength corresponding to a desired temperature; and afterthe temperature setting laser device is removed from the heating-coolingdevice, placing the semiconductor laser device on the heating-coolingdevice while temperature of the heating-cooling device is fixed, andperforming inspection of the semiconductor laser device with the distalend of the measurement probe brought into contact with the semiconductorlaser device.
 7. The semiconductor laser inspection apparatus accordingto claim 3, wherein the spring has a thermal conductivity higher than200 [W/m•K].